revsets: allow single internal - and + characters in symbols (#46)

CHANGELOG.md

@@ -41,6 +41,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   `ui.editor` config. There is also a new `$JJ_EDITOR` environment variable,
   which has even higher priority than the config.
 
+* You can now use `-` and `+` in revset symbols. You used to have to quote
+  branch names like `my-feature` in nested quotes (outer layer for your shell)
+  like `jj co '"my-feature"'`. The quoting is no longer needed.
+
 * The new revset function `connected(x)` is the same as `x:x`.
 
 * The new revset function `roots(x)` finds commits in the set that are not

docs/revsets.md

@@ -34,9 +34,9 @@ typically only one visible commit with a given change ID). A unique prefix of
 the full change ID can also be used. It is an error to use a non-unique prefix.
 
 Use double quotes to prevent a symbol from being interpreted as an expression.
-For example, `"x-1"` is the symbol `x-1`, not the parents of symbol `x`.
+For example, `"x-"` is the symbol `x-`, not the parents of symbol `x`.
 Taking shell quoting into account, you may need to use something like
-`jj log -r '"x-1"'`.
+`jj log -r '"x-"'`.
 
 ### Priority
 

lib/src/revset.pest

@@ -12,10 +12,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-non_period_identifier = @{ (ASCII_ALPHANUMERIC | "_" | "@" | "/")+ }
+identifier_part = @{ (ASCII_ALPHANUMERIC | "_" | "@" | "/")+ }
 identifier = @{
-  (non_period_identifier+ ~ ".")+ ~ non_period_identifier+
-  | non_period_identifier+
+  (identifier_part+ ~ ("." | "-" | "+" ))+ ~ identifier_part+
+  | identifier_part+
 } 
 symbol = {
   identifier

lib/src/revset.rs

@@ -1481,6 +1481,18 @@ mod tests {
         assert_eq!(parse("@"), Ok(checkout_symbol.clone()));
         // Parse a single symbol
         assert_eq!(parse("foo"), Ok(foo_symbol.clone()));
+        // Internal '.', '-', and '+' are allowed
+        assert_eq!(
+            parse("foo.bar-v1+7"),
+            Ok(RevsetExpression::symbol("foo.bar-v1+7".to_string()))
+        );
+        // '.' is not allowed at the beginning or end
+        assert_matches!(parse(".foo"), Err(RevsetParseError::SyntaxError(_)));
+        assert_matches!(parse("foo."), Err(RevsetParseError::SyntaxError(_)));
+        // Multiple '.', '-', '+' are not allowed
+        assert_matches!(parse("foo.+bar"), Err(RevsetParseError::SyntaxError(_)));
+        assert_matches!(parse("foo--bar"), Err(RevsetParseError::SyntaxError(_)));
+        assert_matches!(parse("foo+-bar"), Err(RevsetParseError::SyntaxError(_)));
         // Parse a parenthesized symbol
         assert_eq!(parse("(foo)"), Ok(foo_symbol.clone()));
         // Parse a quoted symbol